Re: [PATCH 2/2] KVM: X86: Implement PV send IPI support

2018-06-30 Thread Wanpeng Li
On Fri, 29 Jun 2018 at 18:49, Paolo Bonzini wrote: > > On 29/06/2018 12:09, Vitaly Kuznetsov wrote: > >> +KVM_FEATURE_PV_SEND_IPI||11 || guest checks this feature > >> bit > >> + || || before enabling > >> paravirtualized > >> +

Re: [PATCH 2/2] KVM: X86: Implement PV send IPI support

2018-06-30 Thread Wanpeng Li
On Fri, 29 Jun 2018 at 18:45, Paolo Bonzini wrote: > > On 29/06/2018 11:51, Wanpeng Li wrote: > > From: Wanpeng Li > > > > Using hypercall to send IPIs by one vmexit instead of one by one for > > xAPIC/x2APIC physical mode and one vmexit per-cluster for x2APIC cluster > > mode. > > > > Even if en

Re: [PATCH 2/2] KVM: X86: Implement PV send IPI support

2018-06-29 Thread Paolo Bonzini
On 29/06/2018 12:09, Vitaly Kuznetsov wrote: >> +KVM_FEATURE_PV_SEND_IPI||11 || guest checks this feature bit >> + || || before enabling >> paravirtualized >> + || || send IPIs. > In case we decide to a

Re: [PATCH 2/2] KVM: X86: Implement PV send IPI support

2018-06-29 Thread Paolo Bonzini
On 29/06/2018 11:51, Wanpeng Li wrote: > From: Wanpeng Li > > Using hypercall to send IPIs by one vmexit instead of one by one for > xAPIC/x2APIC physical mode and one vmexit per-cluster for x2APIC cluster > mode. > > Even if enable qemu interrupt remapping and PV TLB Shootdown, I can still >

Re: [PATCH 2/2] KVM: X86: Implement PV send IPI support

2018-06-29 Thread Vitaly Kuznetsov
Wanpeng Li writes: > From: Wanpeng Li > > Using hypercall to send IPIs by one vmexit instead of one by one for > xAPIC/x2APIC physical mode and one vmexit per-cluster for x2APIC cluster > mode. > > Even if enable qemu interrupt remapping and PV TLB Shootdown, I can still > observe ~14% perfor

[PATCH 2/2] KVM: X86: Implement PV send IPI support

2018-06-29 Thread Wanpeng Li
From: Wanpeng Li Using hypercall to send IPIs by one vmexit instead of one by one for xAPIC/x2APIC physical mode and one vmexit per-cluster for x2APIC cluster mode. Even if enable qemu interrupt remapping and PV TLB Shootdown, I can still observe ~14% performance boost by ebizzy benchmark for